The present invention relates to an LCD (Liquid Crystal Display) advantageously applicable to a digital still camera or similar handy apparatus and more particularly to a device for controlling the brightness of a backlight used to backlight an LCD.
An LCD with an backlight includes a LCD panel to be illuminated by the backlight from the back. Light output from the backlight and transmitted through the LCD panel is recognized as an image. This kind of LCD panel has contrast high enough to allow a person to clearly see an image appearing thereon even in a dark place.
The backlight is implemented by a fluorescent tube which is either a flat fluorescent tube or a sidelight tube. The sidelight tube is a combination of a reflector and a tubular fluorescent tube and feasible for the miniaturization of handy apparatuses with LCDs.
However, the problem with the sidelight tube is that its brightness falls when surrounding temperature falls. It follows that a digital still camera or similar handy apparatus with an LCD panel illuminated by a sidelight tube causes the brightness of the sidelight to fall when the apparatus is used outdoor or at temperatures lower than room temperature. This renders an image appearing on the LCD panel difficult to see.
Technologies relating to the present invention are disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 64-32777, 5-135893, 8-122741 and 9-288262.